I think that using Dune footage and Lawernce footage is still a good idea as long as you somehow explain why some solidiers are dressed different. I wonder if there is any other sci-fi movies that you could get more footage for your "idea" of the clone war battle. There is always the Dune tv mini series. I'll try and think of more later.

Have you thought about using the link that SomethingStarWarsRelated posted (http://fanfilms.theforce.net/User_SearchPI.asp). With that you might be able to get someone to do the fx for those ideas that your not able to do to. But then agian everyone on TFN would never want there precious PT touched to match the OOT